Question

How are you handling form validation with Express and Mongoose? Are you using custom methods, some plugin, or the default errors array?

While I could possibly see using the default errors array for some very simple validation, that approach seems to blow up in the scenario of having nested models.

Answer 1

Mongoose has validation middleware. You can define validation functions for schema items individually. Nested items can be validated too. Furthermore you can define asyn validations. For more information check out the mongoose page.

var mongoose = require('mongoose'),
    schema = mongoose.Schema,
    accountSchema = new schema({
      accountID: { type: Number, validate: [
        function(v){
          return (v !== null);
        }, 'accountID must be entered!'
      ]}
    }),
    personSchema = new schema({
      name: { type: String, validate: [
        function(v){
          return v.length < 20;
        }, 'name must be max 20 characters!']
      },
      age: Number,
      account: [accountSchema]
    }),
    connection = mongoose.createConnection('mongodb://127.0.0.1/test');
    personModel = connection.model('person', personSchema),
    accountModel = connection.model('account', accountSchema);

...
var person = new personModel({
  name: req.body.person.name, 
  age: req.body.person.age,
  account: new accountModel({ accountID: req.body.person.account })
});
person.save(function(err){
  if(err) {
    console.log(err);
    req.flash('error', err);
    res.render('view');
  }
...
});